Gibbs missed the first drawn Test because of an ankle injury but has now been passed fit to play and will replace stand-in opener Boeta Dippenaar.
South Africa will be in buoyant mood after saving the first Test in Galle, a spin-friendly venue that some had expected to produce a Sri Lanka win.
"We now go into the Colombo game with a lot of confidence on a pitch that we can hopefully play well on and put them under pressure," skipper Graeme Smith told reporters.
"We put ourselves under pressure in the first Test match with one bad session," he said. "If we had not had that we could easily have walked away with a win."
"Our standards on the field improved a hell of a lot and the intensity and body language is back."
South Africa's pace attack can look forward to greater assistance at the Sinhalese Sports Club (SSC) after two weeks of damp weather in Colombo.
"There will definitely be more life and assistance for the seam bowlers," groundsman Ranil Abeynaike told reporters on Monday.
"There has been a lot of rain in Colombo in the last two weeks which means there is going to be some moisture in the pitch for at least two days," he added.
South Africa's only other selection dilemma will be whether to replace Nantie Hayward, who was expensive in the first innings in Galle, with Andre Nel.
Sri Lanka coach John Dyson believes his bowlers will also look forward to playing on a bouncier pitch, a surface which he predicts will force a result.
"SSC has definitely got some more pace and bounce and a result is more likely for sure," Dyson told reporters.
"We have got to get away from this notion that we (Sri Lanka) need slow and low turning wickets. We can be a better side on wickets with more bounce and pace."
Sri Lanka may consider calling up young pace bowler Lasith Malinga who bowls with a distinctive round-arm action that surprised Australia's batsmen when Sri Lanka toured in July.
An extra fast bowler could mean dropping leg spinner Upul Chandana and relying on Muttiah Muralitharan as the solitary specialist spinner.
But there are concerns about the form of Muralitharan who toiled unusually hard on the final day in Galle, finishing with just one for 37 from 20 overs.
"Murali would admit that he did not bowl his best in Galle," Dyson said. "We have seen him bowl far better on numerous occasions."
Marvan Atapattu (captain), Sanath Jayasuriya, Kumar Sangakkara, Mahela Jayawardene, Tillakaratne Dilshan, Chaminda Vaas, Farveez Maharoof, Lasith Malinga, Muttiah Muralitharan, Nuwan Zoysa, Thilan Samaraweera, Rangana Herath, Romesh Kaluwitharana, Upul Chandana, Ian Daniel.
Graeme Smith (captain), Jacques Kallis, Boeta Dippenaar, Martin van Jaarsveld, Jacques Rudolph, Andrew Puttick, Herschelle Gibbs, Lance Klusener, Shaun Pollock, Mark Boucher, Makhaya Ntini, Andre Nel, Nantie Hayward, Nicky Boje, Robin Peterson.